compression -Fx "problem"

Hi.

I has compiled a postgresql 7.1.3 into a Debian GNU/Linux. The
"configure" option has the 'max-backends', 'enable-locale' and
'enable-syslog' options.
When I make a:
    pg_dump -O -x -Fc <database> > backupdatabase.sql
The program tell me a "warning" like this:

Archiver: WARNING - requested compression not available in this
installation - archive will be uncompressed

What I make to do for obtain the necessary compression for the "-Fc"
flag and work after with pg_restore?

Thank you very much.

Have a nice day ;-)
TooManySecrets

--
Manuel Trujillo         manueltrujillo@dorna.es
Technical Engineer      http://www.motograndprix.com
Dorna Sports S.L.       +34 93 4702864